+ version 0.1.00 (initial)

RobTillaart · RobTillaart · commit 093fbf040e10 · 2015-03-07T22:44:21.000+01:00
diff --git a/libraries/Temperature/readme.txt b/libraries/Temperature/readme.txt
@@ -0,0 +1,7 @@
+
+Small collection of temperature related functions
+
+TODO: 
+- make all celsius variants of them
+- Class with option F / K / C ?
+
diff --git a/libraries/Temperature/temperature.h b/libraries/Temperature/temperature.h
@@ -0,0 +1,122 @@
+//
+//    FILE: temperature.h
+// VERSION: 0.1.00
+// PURPOSE: temperature functions
+//
+// HISTORY:
+// see temperature.cpp file
+//
+
+#ifndef TEMPERATURE
+#define TEMPERATURE
+
+#include "WProgram.h"
+
+#define TEMPERATURE_VERSION "0.1.00"
+
+//Celsius to Fahrenheit conversion
+double Fahrenheit(double celsius)
+{
+    return 1.8 * celsius + 32;
+}
+
+//Celsius to Kelvin conversion
+double Kelvin(double celsius)
+{
+    return celsius + 273.15;
+}
+
+// dewPoint function NOAA
+// reference: http://wahiduddin.net/calc/density_algorithms.htm
+double dewPoint(double celsius, double humidity)
+{
+    double A0= 373.15/(273.15 + celsius);
+    double SUM = -7.90298*(A0-1);
+    SUM += 5.02808 * log10(A0);
+    SUM += -1.3816e-7 * (pow(10, (11.344*(1-1/A0)))-1) ;
+    SUM += 8.1328e-3*(pow(10,(-3.49149*(A0-1)))-1) ;
+    SUM += log10(1013.246);
+    double VP = pow(10, SUM-3) * humidity;
+    double T = log(VP/0.61078);   // temp var
+    return (241.88*T) / (17.558-T);
+}
+
+// delta max = 0.6544
+// 5x faster than dewPoint()
+// reference: http://en.wikipedia.org/wiki/Dew_point
+double dewPointFast(double celsius, double humidity)
+{
+    double a = 17.271;
+    double b = 237.7;
+    double temp = (a * celsius) / (b + celsius) + log(humidity/100);
+    double Td = (b * temp) / (a - temp);
+    return Td;
+}
+
+//  http://www.ccacac.com/wp-content/uploads/2010/06/Humidex-Graph.pdf - 
+double humidex(double celsius, double DewPoint)
+{
+    double e = 19.833625 - 5417.753 /(273.16 + DewPoint);
+    double h = celsius + 3.3941 * exp(e) - 5.555;
+    return h;
+}
+
+
+// TF = temp in F
+// R = humidity in %
+double heatIndex(double TF, double R)
+{
+    const double c1 = -42.379;
+    const double c2 =  2.04901523;
+    const double c3 = 10.14333127;
+    const double c4 = -0.22475541;
+    const double c5 = -0.00683783;
+    const double c6 = -0.05481717;
+    const double c7 =  0.00122874;
+    const double c8 =  0.00085282;
+    const double c9 = -0.00000199;
+
+    double A = (( c5 * TF) + c2) * TF + c1;
+    double B = (((c7 * TF) + c4) * TF + c3) * R;
+    double C = (((c9 * TF) + c8) * TF + c6) * R * R;
+
+    return A + B + C;
+}
+
+// less constants => faster but slightly inaccurate
+// TF = temp in F
+// R = humidity in %
+double heatIndexFast(double TF, double R)
+{
+    const double c1 = -42.379;
+    const double c2 =  2.04901523;
+    const double c3 = 10.14333127;
+    const double c4 = -0.22475541;
+
+    double A = c2 * TF + c1;
+    double B = (c4 * TF + c3) * R;
+
+    return A + B;
+}
+
+// integer version
+// TF = temp in F
+// R = humidity in %
+int heatIndexFastInt(int TF, int R)
+{
+    // consts multiplied by 1024
+    long c1 = -43396;
+    long c2 = 2098;
+    long c3 = 10387;
+    long c4 = -230;
+
+    long A = c2 * TF + c1;  // so A is x 1024
+    long B = (c4 * TF + c3) * R;  // and B too
+
+    return (A + B + 512) / 1024; // division becomes a shift; +512 is for rounding
+}
+
+#endif
+//
+// END OF FILE
+//
